Steam generator



Patented May 27, 1947 UNITED STATE S PATENT OFFICE STEAM GENERATOR Application October 12, 1944, Serial No. 558,321

8 Claims.

1 This invention relates to steam generators, and more particularly to steam generators of the water tube type having a longitudinally extending steam-and-water drum and a combustion chamber located in front of the drum.

It is one object of the invention to provide a water tube steam generator of relatively high capacity which can be assembled as a unit and yet be sufficiently compact for railway shipment.

It is a further object of the invention to provide a water tube steam generator which will have a relatively high capacity in proportion to the vertical space occupied.

It is a further object of the invention to provide a Water tube generator having a combustion chamber located in front of a longitudinally extending steam-and-water drum, and particularly to provide a novel and effective arrangement of water tubes to protect the front end of the drum from excessive heat.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one em bodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a longitudinal vertical section through a steam generator, taken on the line |-l of Fig. 2;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a section taken on the line 3-3 of Fig. 1;

Fig. 4 is a section taken on the line 4-4 of Fig. 1; and

Fig. 5 is a section taken on the line 5-5 of Fig. 1. I

The embodiment illustrated comprises a longi.. tudinally extending steam-and-water drum l0 and two longitudinally extending water drums or headers ll located therebeneath. These lower drums H are substantially coextensive in length with the upper drum l0, and. they are considerably smaller in diameter than the upper drum, in fact approximately one-half the diameter thereof. The lower drums H are positioned at a common level and their axes are preferably spaced apart a distance somewhat exceeding the diameter of the upper drum ID. The upper drum is connected to the two lower drums by transverse rows of upright water tubes l2 forming the convection heating surface of the steam generator.

If superheated steam is required, some of the Water tubes l2 may be omitted adjacent the front portions of the drums to provide a space for a tubular superheater M. The upper ends of the superheater tubes are connected to the steamand-water drum l0 and enclosed by a box [5 within the drum. This box is connected by tubes is to the interior of a chamber or conduit l8 in the steam space of the drum Ill and communicating with the rear portion thereof. The lower ends of the superheater tubes l4 are connected to a steam outlet header l9 spacedoutwardly from one of the lower drums I I. The various parts as so far described ar mounted with a setting including opposed upright side walls 20 which extend forwardly for a considerable distance beyond the drums to pro-- vide a furnace or combustion chamber 22. The front wall 23 of the combustion chamber is pro.. vided with a burner opening 24 for the introduction of air and a suitable fuel, such as oil, which is burned in suspension. The hot gaseous products of combustion flow rearwardly into contact with the superheater l4 and the water tubes l2, the gases eventually escaping upwardly through outlet ducts 26 on opposite side of the drum I0 and adjacent to the rear wall 21 of the setting. Suitable transverse vertical bafiies 28 are provided among the water tubes l2 to direct the gases into a tortuous path.

At the rear of the combustion chamber 22 there is provided a bridge wall 30 of refractory material with its upper edge spaced downwardly from the front portion of the upper drum Ill. The lower part of this wall slopes forwardly and downwardly in front of the lower drums H to protect the front ends of these drums from the radiant heat of the furnace. This wall 30 is supported and cooled by a transverse row of upright water tubes 3l with thier upper ends connected to the drum l0 and their lower ends connected to a transverse header 32. This header is located immediately in front of the drums l I and connected to each of these drums by a large tube or nipple 33.

The side walls 20 of the combustion chamber 22 are protected by upright water wall tubes 35 which are connected at their lower ends to longitudinally extending headers 36. The rear por tions of the headers 36 are connected to the transverse header 32. The lower surfaces of the headers 32 and 36 are positioned at substantially the same level as the lower surfaces'of the lower drums ll. The upper portions of the water wall tubes 35 are bent laterally inward to form a support for the roof 31 of the furnace 22,'the tubes from opposite sides crossing one another along a line corresponding approximately to a forward projection of the axis of the drum [0. The upper ends of the tubes 35 are connected to longitudinally extending headers 38 which are connected at their rear ends to opposite sides of the drum I above the normal water level therein. This construction provides a relatively high combustion space; without adding any-thing toithe over; all height of the steam. generator-.-

Because of the height of the furnace relative to the upper drum Ill, it becomes important to; protect the front end of this drum from excessive heat. For this purpose a layer of refractory ma. terial 40 is applied to this drumhead, buta still.

further protection will ordinarily be. required;

Accordingly I preferably arrange a protecting; screen of water tubes 42 in the upper rear portion of the furnace 22, close to the drum head": Flie lower portions of these tubes 42 form water wall tubes which extend upwardly from the headers 36 and adjacent the side. walls 2il, rearwardly of the. tubes 33." The" upper portions ofthetub'e 4t are bent. laterally 1 inwardiin' a manner similar to, the tubes 35, the tubes from oppositesidcs. crossing one another and connecting attheir. upper ends With'the'headers BBt Thetubes l'thoweverj cross. atlower elevations than the tubes and. the points of crossing; are progressively lower. toward the rear; Consequently the crossed portions of the; tubes" 42' form; a very" eifective water cooled screen to shield the front; end of? the drum; ill from ra'diant'heat, besidesdeflectingjthe'hotgases downwardly away. from the" drum. In. the embodiment' illustratedthere are eight of'the, tubes. 41"; but this: number" may." be: either increasedor. decreased" withoutdeparting from the spirit: of the; invention:

In the operation of; the. apparatus. water; from the lower drums. lil". will; flow throughthanipples. 33170; the header 32 and'thence. to, theheaderslfil thereby'ensuring' an adequate water supply. tothe. loweren'd's of the, water, tub.es.3l;.35;andl42i Since. thesetubes' are exposed to the. radiantheatlofjthe. burning; fuel, they" willi generate, steam. at aliigh. rate and dischargethi's steam, intdthe upper drum. H1, Additionallsteam. will; be. generated? in the. watertubes l2, particularly. in. those. nearestv the furnace; The steam willileavethe upper. drum. through the conduit lB,-, tubes. 16, and; box. 15,, thence. entering the, superheater. tubes 14; and escaping through. theheaden L91 toa place ofrusel. The hot gases from" thefurnace. Z2 'wilhflow. rear.- wardly'overthetop of the bridge. wallflliinto con: tact with the super-heater 1'4. andf'wat'er tubes I 2,. eventually escapinathrough' theioutletjductszli.

The 'variouspressure' partscan' be. shop assent-- bled into a structure having; an over=al1 height; determined by the-distance from the. bottom surfaces ofg thelower'drums' I I to the. topsurfajcaof. the upper-drum Ill. Withsuch astructur'e built within" the limits. of ordinary. railway clearances, an unusually large steam generating capacity is. obtainable. This is brought about largely'by, the. novelarrangement. of the: water cooled combustion chamber 22." By providing the; two. lower. drums II with diametersiwhichare smalliniproportion to thediametertofj the upper. drum I D} it be'c0m'es:feasib1e tc widen the: setting. andlt'o. in.- crease" the number ofconvection water, tubes. I22 This. is an additional feature whichcontributes tohigh'capacity withina relatively low. headroom. Thehighfurnace 22'not onlyensuresa large fuel-1- burning capacity; but it; also adds to, the efficiency of'combustion.

Having thus described my invention, what. I

4 claim as new and desire to secure by Letters Patent is:

1. A steam generator comprising a longitudinally extending steam-and-water drum, transverse rows of upright water tubes beneath the drum and connected at their upper ends to the drum, means providing a combustion chamber in front'ofrthe water tubes: and drumiandv arranged to: supply; hot. gases for heating the water tubes, upright water wall tubes at one side of the combustion chamber, the upper portions of the water wall. tubes being bent laterally to extend across the combustion chamber and support the roof thereofi ata substantial distance above the lower surface of: the: drum; and other upright water wall tubes at one sidemfthe combustion chamber with their. upper. portions. bent laterally to extend beneath the roof and across the front end of the dnuniassascreen to shield the drum from the heat in said chamber.

2. A- steam generatorcomprising;at longitudinally: extending steam-and-waten drum;. transverse rows. of upright water: tubes, beneath; the drum. and connected atitheiri upper-endsatdth'e drum, means providing: a combustion chamberrin frontofthe waterftubespuprightwaten wall tubes at b-oth sidesof the combustionchamber, the-um pen portions. of the water Wall tubes-being; bent laterally to-support the roofof; the; combustion chamber. andcrossing ODG'aHOthEITatxQI" substantial distance:- above rthe lowerasuriaceio-fi the; drum; and other uprightwatenwall: tubessat bothzsides: of the combustion chamberrearwardly of! the first-mentioned water'wall tubes, the upperaportionsof the saidwothenwaterwalltubes;being'benti laterallyto cross one another. and form azscreen: so -located. as; to: shield? the. front t end: of theidiz-unr from the:heatin said: chamber.

3:. A steam; generator. comprising: a: longitudia nally extending steam-and-water ditunn. transs verse-rows of upright. water-tubes beneath: the drum and connected: at, their upper ends: to 1 the' drum; means pno-vidingaacombustioni chamber: in frontof the water tubesgupriflxtwatenwall tubes at both sides of the combustion-chamber; thezup per. portions of the water: wall: tubes being bent laterally to support the: roof: off the combustioni chamber and. crossing; one; another. at approxi mately the height: of? the: axis: of: the: drunr. and othen upright vt'aterrwallrtubessats' both SidGSiOfz the combustion chamber rearwardly of the;fir'st" mentionedwater wall tubes, the upper portions oi the said other water wall tubes being bent later allyto:crossioneahothenat pointswhich arezsuccessively lower from front to rear and form'tla screen so located as tosliield. the front endwf the drum from the heat in said chamber:

4; A. steam generator: comprising a longitudlnally extending steam-and-Water drum, twolon gitudinallyextending: water: drums: located beneathth'e steameandi-waterrdrum; transverse rows ofiupright watertubescnnnectingithe steamean d water drumiwithlthecwaten'drumssmeans provid ing;a=combustion-chamberzim front ofithe water: tubesrand arranged .tosupplyrhot gasesifon heata ing thewater-tubes, 1a transverse;headen inifrontt of the :waterdrums, nipples connectingih-aheaden to the: front ends of;- the; water drums-l as trans-.- versejrows on uprig-hhwater tubes: connecting; the. header. with. the-steam eand-watersdrum; two'z-lone gitudinallv extending headers located:at:oppositesides of; the: combustion chamber andrconnected'; to. the, transverse header; and: water: wall; tubess extending. upwardly from the longitudinally; exttending.headers, thelupper ends oi thesaid water wall tubes communicating with the steam-andwater drum.

5. A steam generator comprising a longitudinally extending steam-and-water drum, two longitudinally extending water drums located beneath the steam-and-water drum on opposite sides of the axis thereof, the water drums being considerably smaller in diameter than the steamand-water drum, transverse rows of upright water tubes connecting the steam-and-water drum with the water drums, means providing a combustion chamber in front of the water tubes, a transverse header in front of the wate drums, nipples connecting the header to the front ends of the water drums, a transverse row of upright water tubes connecting the header with the steam-and-water drum, two longitudinally extending headers located at opposite sides of the combustion chamber and connected to the transverse header, the lower surfaces of the two longitudinally extending headers and of the transverse header being in ap proximately the same horizontal plane as the lower surfaces of the water drums, and water wall tubes extending upwardly from the longitudinally extending headers, the upper ends of the water wall tubes communicating with the steam-andwater drum.

6. A steam generator comprising a longitudinally extending steam-and-water drum, two longitudinally extending water drums located beneath the steam-and-water drum on opposite sides of the axis thereof, the water drums being considerably smaller in diameter than the steamand-water drum, transverse rows of upright water tubes connecting the steam-and-water drum with the water drums, means providing a combustion chamber in front of the water tubes, a transverse header in front of the water drums, nipples connecting the header to the front ends of the water drums, a transverse row of upright water tubes connecting the header with the steam-and-water drum, two longitudinally extending headers located at opposite sides of the combustion chamber and connected to the transverse header, water wall tubes extending upwardly from the longitudinally extending headers, the upper portions of the water wall tubes being bent laterally to support the roof of the combustion chamber and crossing one another at a substantial distance above the lower surface of the steam-and-water drum, other water wall tubes extending upwardly from the longitudinally extending headers rearwardly of the first-mentioned water wall tubes, the upper portions of the said other water wall tubes being bent laterally to cross one another and form a screen so located as to shield the front end of the steam-and-water drum from the heat in said chamber, and means connecting the upper ends of the water wall tubes to the steam-andwater drum.

7. A steam generator comprising a longitudinall extending steam-and-water drum, two longitudinally extending water drums located beneath the steam-and-water drum on opposite sides of the axis thereof, the water drums being considerably smaller in diameter than the steamand-water drum, transverse rows of upright water tubes connecting the steam-and-water drum with the water drums, means providing a combustion chamber in front of the water tubes, a transverse header in front of the water drums, nipples connecting the header to the front ends of the water drums, a transverse row of upright water tubes connecting the header with the steam-andwater drum, two longitudinally extending headers located at opposite sides of the combustion chamber and connected to the transverse header, water wall tubes extending upwardly from the longitudinally extending headers, the upper portions of the water wall tubes being bent laterally to support the roof of the combustion chamber and crossing one another at a substantial distance above the lower surface of the steam-and-water drum, other water wall tubes extendin upwardly from the longitudinally extending headers rearwardly of the first-mentioned water wall tubes, the upper portions of the said other water wall tubes being bent laterally to cross one another at points which are successively lower from front to rear and form a screen so located as to shield the front end of the steam-and-water drum from the heat in said chamber, and two headers extending longitudinally above the combustion chamber and connected to opposite sides of the steam-andwater drum, the upper ends of the water wall tubes being connected to the last-mentioned headers.

8. A steam generator comprising a longitudinally extending steam-and-water drum, transverse rows of upright water tubes beneath the drum and connected at their upper ends to the drum, means providing a combustion chamber in front of the water tubes and drum and arranged to supply hot gases for heating the water tubes, the combustion chamber having a roof located at a substantial distance above the lower surface of the drum, and upright water wall tubes at one side of the combustion chamber with their upper portions bent laterally to extend beneath the roof and across the front end of the drum as a screen to shield the drum from the heat in said chamber.

MAX H. KUI-INER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,360,260 Nagel Oct. 10, 1944 2,097,268 Best Oct. 26, 1937 465,164 Cowles Dec. 15, 1891 

